Setting The Operating Vacuum Level - Labconco FreeZone Triad 74000 Series User Manual

The display will show:
VACUUM UNITS:
MBar
 At any time the DISPLAY button can be pressed to select a different
function.

Setting the Operating Vacuum Level

The vacuum level may be manually set by the user to optimize the freeze dry
process. Normally, the sublimation rate will increase if there is less vacuum
(a higher pressure) in the Triad Freeze Dry System. A good starting place is
to set the vacuum to a level that will hold the sample temperature
approximately 10°C cooler than the eutectic temperature. Adjustments to the
vacuum level must be made for various freeze drying conditions. Factors that
must be considered are whether the sample is freeze dried on heated shelves
or in glassware attached to manifold valves, the volatility of the sample itself,
the size of the sample and the heat energy supplied to the sample. When the
vacuum control is set to operate at less vacuum, the ice holding capacity of
the collector may be decreased.
Some guidelines for setting the Triad Freeze Dry System are shown below.
These show pre-freezing temperature and vacuum levels. The user of the
specific samples that are being freeze dried must determine exact protocols.
Material Solidification/Eutectic
Bacteria, Virus -40°C and Colder
Milk -5 to -13
Fungi -40 and Colder
-25 to –50
Vegetable Tissue
-30 to –40
Human Tissue
-10 to –25
Blood Plasma
-30 to –40
Vaccine
Product Service 816-333-8811 or 1-800-522-7658
Chapter 4: Operating Instructions
Pa Torr
Pre-Freeze
Temperature Temperatures
-50°C and Colder
-15 to -23
-50 and Colder
-35 to –60
-40 to –50
-20 to –35
-40 to –50
Vacuum Set Point
0.404 mBar and Lower
1.65 to 0.77
0.04 and Lower
0.22 to 0.01
0.12 to 1.04
1.03 to 0.22
0.12 to 0.04
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